#!/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby
# This script installs to /usr/local only. To install elsewhere you can just
# untar https://github.com/Homebrew/brew/tarball/master anywhere you like or
# change the value of HOMEBREW_PREFIX.
HOMEBREW_PREFIX = "/usr/local".freeze
HOMEBREW_REPOSITORY = "/usr/local/Homebrew".freeze
HOMEBREW_CACHE = "#{ENV["HOME"]}/Library/Caches/Homebrew".freeze
HOMEBREW_OLD_CACHE = "/Library/Caches/Homebrew".freeze
BREW_REPO = "https://github.com/Homebrew/brew".freeze
CORE_TAP_REPO = "https://github.com/Homebrew/homebrew-core".freeze

# TODO: bump version when new macOS is released
MACOS_LATEST_SUPPORTED = "10.13".freeze
# TODO: bump version when new macOS is released
MACOS_OLDEST_SUPPORTED = "10.11".freeze

# no analytics during installation
ENV["HOMEBREW_NO_ANALYTICS_THIS_RUN"] = "1"
ENV["HOMEBREW_NO_ANALYTICS_MESSAGE_OUTPUT"] = "1"

module Tty
  module_function

  def blue
    bold 34
  end

  def red
    bold 31
  end

  def reset
    escape 0
  end

  def bold(n = 39)
    escape "1;#{n}"
  end

  def underline
    escape "4;39"
  end

  def escape(n)
    "\033[#{n}m" if STDOUT.tty?
  end
end

class Array
  def shell_s
    cp = dup
    first = cp.shift
    cp.map { |arg| arg.gsub " ", "\\ " }.unshift(first).join(" ")
  end
end

def ohai(*args)
  puts "#{Tty.blue}==>#{Tty.bold} #{args.shell_s}#{Tty.reset}"
end

def warn(warning)
  puts "#{Tty.red}Warning#{Tty.reset}: #{warning.chomp}"
end

def system(*args)
  abort "Failed during: #{args.shell_s}" unless Kernel.system(*args)
end

def sudo(*args)
  args.unshift("-A") unless ENV["SUDO_ASKPASS"].nil?
  ohai "/usr/bin/sudo", *args
  system "/usr/bin/sudo", *args
end

def getc
  system "/bin/stty raw -echo"
  if STDIN.respond_to?(:getbyte)
    STDIN.getbyte
  else
    STDIN.getc
  end
ensure
  system "/bin/stty -raw echo"
end

def wait_for_user
  puts
  puts "Press RETURN to continue or any other key to abort"
  c = getc
  # we test for \r and \n because some stuff does \r instead
  abort unless (c == 13) || (c == 10)
end

class Version
  include Comparable
  attr_reader :parts

  def initialize(str)
    @parts = str.split(".").map { |p| p.to_i }
  end

  def <=>(other)
    parts <=> self.class.new(other).parts
  end
end

def force_curl?
  ARGV.include?("--force-curl")
end

def macos_version
  @macos_version ||= Version.new(`/usr/bin/sw_vers -productVersion`.chomp[/10\.\d+/])
end

def should_install_command_line_tools?
  return false if force_curl?
  return false if macos_version < "10.9"
  if macos_version > "10.13"
    !File.exist?("/Library/Developer/CommandLineTools/usr/bin/git")
  else
    !File.exist?("/Library/Developer/CommandLineTools/usr/bin/git") ||
      !File.exist?("/usr/include/iconv.h")
  end
end

def git
  return false if force_curl?

  @git ||= if ENV["GIT"] && File.executable?(ENV["GIT"])
    ENV["GIT"]
  elsif Kernel.system "/usr/bin/which -s git"
    "git"
  else
    exe = `xcrun -find git 2>/dev/null`.chomp
    exe if $? && $?.success? && !exe.empty? && File.executable?(exe)
  end

  return unless @git
  # Github only supports HTTPS fetches on 1.7.10 or later:
  # https://help.github.com/articles/https-cloning-errors
  `#{@git} --version` =~ /git version (\d\.\d+\.\d+)/
  return if $1.nil?
  return if Version.new($1) < "1.7.10"

  @git
end

def user_only_chmod?(d)
  return false unless File.directory?(d)
  mode = File.stat(d).mode & 0777
  # u = (mode >> 6) & 07
  # g = (mode >> 3) & 07
  # o = (mode >> 0) & 07
  mode != 0755
end

def chmod?(d)
  File.exist?(d) && !(File.readable?(d) && File.writable?(d) && File.executable?(d))
end

def chown?(d)
  !File.owned?(d)
end

def chgrp?(d)
  !File.grpowned?(d)
end

# Invalidate sudo timestamp before exiting (if it wasn't active before).
Kernel.system "/usr/bin/sudo -n -v 2>/dev/null"
at_exit { Kernel.system "/usr/bin/sudo", "-k" } unless $?.success?

# The block form of Dir.chdir fails later if Dir.CWD doesn't exist which I
# guess is fair enough. Also sudo prints a warning message for no good reason
Dir.chdir "/usr"

####################################################################### script
abort "See Linuxbrew: http://linuxbrew.sh/" if RUBY_PLATFORM.to_s.downcase.include?("linux")
abort "Mac OS X too old, see: https://github.com/mistydemeo/tigerbrew" if macos_version < "10.5"
abort "Don't run this as root!" if Process.uid.zero?
abort <<-EOABORT unless `dsmemberutil checkmembership -U "#{ENV["USER"]}" -G admin`.include? "user is a member"
This script requires the user #{ENV["USER"]} to be an Administrator.
EOABORT
# Tests will fail if the prefix exists, but we don't have execution
# permissions. Abort in this case.
abort <<-EOABORT if File.directory?(HOMEBREW_PREFIX) && (!File.executable? HOMEBREW_PREFIX)
The Homebrew prefix, #{HOMEBREW_PREFIX}, exists but is not searchable. If this is
not intentional, please restore the default permissions and try running the
installer again:
    sudo chmod 775 #{HOMEBREW_PREFIX}
EOABORT

# TODO: bump version when new macOS is released
if macos_version > MACOS_LATEST_SUPPORTED ||
   macos_version < MACOS_OLDEST_SUPPORTED

  who = "We"
  if macos_version > MACOS_LATEST_SUPPORTED
    what = "pre-release version"
  elsif macos_version < MACOS_OLDEST_SUPPORTED
    who << " (and Apple)"
    what = "old version"
  else
    return
  end
  ohai "You are using macOS #{macos_version.parts.join(".")}."
  ohai "#{who} do not provide support for this #{what}."

  puts <<-EOS
This installation may not succeed.
After installation, you will encounter build failures and other breakages.
Please create pull-requests instead of asking for help on Homebrew's
GitHub, Discourse, Twitter or IRC. As you are running this #{what},
you are responsible for resolving any issues you experience.

  EOS
end

ohai "This script will install:"
puts "#{HOMEBREW_PREFIX}/bin/brew"
puts "#{HOMEBREW_PREFIX}/share/doc/homebrew"
puts "#{HOMEBREW_PREFIX}/share/man/man1/brew.1"
puts "#{HOMEBREW_PREFIX}/share/zsh/site-functions/_brew"
puts "#{HOMEBREW_PREFIX}/etc/bash_completion.d/brew"
puts HOMEBREW_REPOSITORY.to_s

group_chmods = %w[ bin bin/brew etc Frameworks include lib sbin share var
                   etc/bash_completion.d lib/pkgconfig var/log
                   share/aclocal share/doc share/info share/locale share/man
                   share/man/man1 share/man/man2 share/man/man3 share/man/man4
                   share/man/man5 share/man/man6 share/man/man7 share/man/man8].
               map { |d| File.join(HOMEBREW_PREFIX, d) }.
               select { |d| chmod?(d) }
# zsh refuses to read from these directories if group writable
zsh_dirs = %w[share/zsh share/zsh/site-functions].
           map { |d| File.join(HOMEBREW_PREFIX, d) }
user_chmods = zsh_dirs.select { |d| user_only_chmod?(d) }
chmods = group_chmods + user_chmods
chowns = chmods.select { |d| chown?(d) }
chgrps = chmods.select { |d| chgrp?(d) }
mkdirs = %w[Cellar Homebrew Frameworks bin etc include lib opt sbin share share/zsh share/zsh/site-functions var].
         map { |d| File.join(HOMEBREW_PREFIX, d) }.
         reject { |d| File.directory?(d) }

unless group_chmods.empty?
  ohai "The following existing directories will be made group writable:"
  puts(*group_chmods)
end
unless user_chmods.empty?
  ohai "The following existing directories will be made writable by user only:"
  puts(*user_chmods)
end
unless chowns.empty?
  ohai "The following existing directories will have their owner set to #{Tty.underline}#{ENV["USER"]}#{Tty.reset}:"
  puts(*chowns)
end
unless chgrps.empty?
  ohai "The following existing directories will have their group set to #{Tty.underline}admin#{Tty.reset}:"
  puts(*chgrps)
end
unless mkdirs.empty?
  ohai "The following new directories will be created:"
  puts(*mkdirs)
end
if should_install_command_line_tools?
  ohai "The Xcode Command Line Tools will be installed."
end

wait_for_user if STDIN.tty? && !ENV["TRAVIS"]

if File.directory? HOMEBREW_PREFIX
  sudo "/bin/chmod", "u+rwx", *chmods unless chmods.empty?
  sudo "/bin/chmod", "g+rwx", *group_chmods unless group_chmods.empty?
  sudo "/bin/chmod", "755", *user_chmods unless user_chmods.empty?
  sudo "/usr/sbin/chown", ENV["USER"], *chowns unless chowns.empty?
  sudo "/usr/bin/chgrp", "admin", *chgrps unless chgrps.empty?
else
  sudo "/bin/mkdir", "-p", HOMEBREW_PREFIX
  sudo "/usr/sbin/chown", "root:wheel", HOMEBREW_PREFIX
end

unless mkdirs.empty?
  sudo "/bin/mkdir", "-p", *mkdirs
  sudo "/bin/chmod", "g+rwx", *mkdirs
  sudo "/bin/chmod", "755", *zsh_dirs
  sudo "/usr/sbin/chown", ENV["USER"], *mkdirs
  sudo "/usr/bin/chgrp", "admin", *mkdirs
end

[HOMEBREW_CACHE, HOMEBREW_OLD_CACHE].each do |cache|
  sudo "/bin/mkdir", "-p", cache unless File.directory? cache
  sudo "/bin/chmod", "g+rwx", cache if chmod? cache
  sudo "/usr/sbin/chown", ENV["USER"], cache if chown? cache
  sudo "/usr/bin/chgrp", "admin", cache if chgrp? cache
end

if should_install_command_line_tools?
  ohai "Searching online for the Command Line Tools"
  # This temporary file prompts the 'softwareupdate' utility to list the Command Line Tools
  clt_placeholder = "/tmp/.com.apple.dt.CommandLineTools.installondemand.in-progress"
  sudo "/usr/bin/touch", clt_placeholder
  clt_label = `/usr/sbin/softwareupdate -l | grep -B 1 -E "Command Line (Developer|Tools)" | awk -F"*" '/^ +\\*/ {print $2}' | sed 's/^ *//' | tail -n1`.chomp
  ohai "Installing #{clt_label}"
  sudo "/usr/sbin/softwareupdate", "-i", clt_label
  sudo "/bin/rm", "-f", clt_placeholder
  sudo "/usr/bin/xcode-select", "--switch", "/Library/Developer/CommandLineTools"
end

# Headless install may have failed, so fallback to original 'xcode-select' method
if should_install_command_line_tools? && STDIN.tty?
  ohai "Installing the Command Line Tools (expect a GUI popup):"
  sudo "/usr/bin/xcode-select", "--install"
  puts "Press any key when the installation has completed."
  getc
  sudo "/usr/bin/xcode-select", "--switch", "/Library/Developer/CommandLineTools"
end

abort <<-EOABORT if `/usr/bin/xcrun clang 2>&1` =~ /license/ && !$?.success?
You have not agreed to the Xcode license.
Before running the installer again please agree to the license by opening
Xcode.app or running:
    sudo xcodebuild -license
EOABORT

ohai "Downloading and installing Homebrew..."
Dir.chdir HOMEBREW_REPOSITORY do
  if git
    # we do it in four steps to avoid merge errors when reinstalling
    system git, "init", "-q"

    # "git remote add" will fail if the remote is defined in the global config
    system git, "config", "remote.origin.url", BREW_REPO
    system git, "config", "remote.origin.fetch", "+refs/heads/*:refs/remotes/origin/*"

    # ensure we don't munge line endings on checkout
    system git, "config", "core.autocrlf", "false"

    args = git, "fetch", "origin", "master:refs/remotes/origin/master",
           "--tags", "--force"
    system(*args)

    system git, "reset", "--hard", "origin/master"

    system "ln", "-sf", "#{HOMEBREW_REPOSITORY}/bin/brew", "#{HOMEBREW_PREFIX}/bin/brew"

    system "#{HOMEBREW_PREFIX}/bin/brew", "update", "--force"
  else
    # -m to stop tar erroring out if it can't modify the mtime for root owned directories
    # pipefail to cause the exit status from curl to propagate if it fails
    curl_flags = "fsSL"
    curl_flags += "k" if macos_version < "10.6"
    core_tap = "#{HOMEBREW_PREFIX}/Homebrew/Library/Taps/homebrew/homebrew-core"
    system "/bin/bash -o pipefail -c '/usr/bin/curl -#{curl_flags} #{BREW_REPO}/tarball/master | /usr/bin/tar xz -m --strip 1'"

    system "ln", "-sf", "#{HOMEBREW_REPOSITORY}/bin/brew", "#{HOMEBREW_PREFIX}/bin/brew"

    system "/bin/mkdir", "-p", core_tap
    Dir.chdir core_tap do
      system "/bin/bash -o pipefail -c '/usr/bin/curl -#{curl_flags} #{CORE_TAP_REPO}/tarball/master | /usr/bin/tar xz -m --strip 1'"
    end
  end
end

warn "#{HOMEBREW_PREFIX}/bin is not in your PATH." unless ENV["PATH"].split(":").include? "#{HOMEBREW_PREFIX}/bin"

ohai "Installation successful!"
puts

# Use the shell's audible bell.
print "\a"

# Use an extra newline and bold to avoid this being missed.
ohai "Homebrew has enabled anonymous aggregate user behaviour analytics."
puts <<-EOS
#{Tty.bold}Read the analytics documentation (and how to opt-out) here:
  #{Tty.underline}https://docs.brew.sh/Analytics.html#{Tty.reset}

EOS

if git
  Dir.chdir HOMEBREW_REPOSITORY do
    system git, "config", "--local", "--replace-all", "homebrew.analyticsmessage", "true"
  end
end

ohai "Next steps:"

if macos_version < "10.9" && macos_version > "10.6"
  `/usr/bin/cc --version 2> /dev/null` =~ /clang-(\d{2,})/
  version = $1.to_i
  if version < 425
    puts "- Install the #{Tty.bold}Command Line Tools for Xcode:"
    puts "    #{Tty.underline}https://developer.apple.com/downloads#{Tty.reset}"
  end
elsif !File.exist? "/usr/bin/cc"
  puts "- Install #{Tty.bold}Xcode:"
  puts "    #{Tty.underline}https://developer.apple.com/xcode#{Tty.reset}"
end

unless git
  puts "- Run `brew update --force` to complete installation by installing:"
  puts "    #{HOMEBREW_PREFIX}/share/doc/homebrew"
  puts "    #{HOMEBREW_PREFIX}/share/man/man1/brew.1"
  puts "    #{HOMEBREW_PREFIX}/share/zsh/site-functions/_brew"
  puts "    #{HOMEBREW_PREFIX}/etc/bash_completion.d/brew"
  puts "    #{HOMEBREW_REPOSITORY}/.git"
end

puts "- Run `brew help` to get started"
puts "- Further documentation: "
puts "    #{Tty.underline}https://docs.brew.sh#{Tty.reset}"
